<!doctype html>
<html lang="zh-CN">
  <head>
    <meta charset="utf-8" />
    <title>Hulk</title>
    <link rel="stylesheet" href="popup.css" />
  </head>
  <body>
    <header class="hero">
      <h1>改变背景颜色</h1>
      <p>点击下方按钮将当前页面背景色改为绿色</p>
    </header>
    <main>
      <button id="changeColorBtn" type="button">改变颜色</button>
      <p id="statusMessage" class="status" role="status" aria-live="polite"></p>
    </main>
    <script src="popup.js"></script>
  </body>
</html>

